This invention relates to radio receiver antenna arrangements.
More particularly the invention relates to radio receiver antenna arrangements of the kind comprising a radio antenna and a radio frequency (r.f.) amplifier associated therewith for amplifying signals picked up by the antenna prior to their application to a radio receiver. In such an arrangement the amplifier, which is typically referred to as a pre-amplifier, is normally preset to operate at all frequencies within a desired fixed bandwidth, which may be quite broad.
One difficulty experienced with such antenna arrangements is that in areas of intense r.f. field strength, i.e. near a transmitter, the amplifier may be overloaded and/or produce intermodulation products and/or may cause overload effects in the receiver.